Lithium batteries, sometimes described as lithium-ion batteries, offer the promise of high energy density because lithium is a very light element. They are used in lap top computers, power tools, and other portable devices that can use a source of relatively low potential electrical energy. Lithium batteries are also being developed for applications in automotive vehicles.
Metallic lithium, often intercalated in suitable layered carbon material as lithium ions, has been employed as a negative electrode for rechargeable lithium batteries. During discharge of the battery, lithium metal in the negative electrode is oxidized to lithium ions (Li+) which enter the electrolyte, and during charging lithium ions in the electrolyte are reduced to lithium metal and re-deposited in the electrode. However, non-uniform deposition of lithium during the charging process generates dendritic lithium that may present difficulties in the operation of the cell. Much work has been expended to solve the lithium dendritic growth problem of the lithium battery, using various inhibitors and additives in the cells. One commercial solution has been to move to Li-ion systems in which the lithium metal negative electrode is replaced by a carbon-based electrode. However, the capacity of the carbon electrode is appreciably less than that of lithium metal. Thus, there is a motivation to devise alternative electrode materials for lithium-ion batteries.
There is a need for improved negative electrode compositions for lithium batteries.